The great-circle distance between San Francisco (SFO) and Auckland (AKL) is about 11,000 km (6,800 miles).
Air New Zealand operates a year-round non-stop service (NZ7/8) using a 787-9. Block time is 12 hr 45 min – 13 hr 30 min westbound (SFO→AKL) and roughly 11 hr 30 min eastbound thanks to tailwinds.
Carriers like Qantas (via SYD), United (via LAX/HNL), and Hawaiian (via HNL) offer connecting itineraries. Total travel time typically ranges from 15 to 20+ hours depending on layover length.
Schedules may shift between summer (NZ summer = Dec–Feb) and winter; always verify the operating timetable for your travel dates.